SU1303911A1 - Method of dynamic calibration of transducers of solution salinity - Google Patents

Abstract

The invention relates to the field of studying the salinity of liquid media and can be used in the dynamic calibration of sensors (converters), salinity and electrical conductivity. The purpose of the invention is to expand the working range of dynamic graduation towards high frequencies. The essence of the invention is the creation inside the liquid of a spatial cylindrical region with uniformly alternating regions having different salinity (in particular, zero). Regions with reduced (or zero) salinity are formed at the intersection of the salt trail left during the sedimentation of the salt crystal in the liquid and the laser beam. In the forgula of the invention, the boundaries of the range of sizes of salt crystals and the range of absorption coefficients of laser radiation (from which the wavelength of the laser radiation is chosen) are indicated. Two graduation modes are given. 2 з.п f-ly. 1 il. with iS (L W) o SLE x

Description

one

The invention relates to technical physics and can be used for dynamic calibration of salinity and electrical conductivity meters of solutions.

The aim of the invention is to extend the operating range of the dynamic graduation towards the high frequencies.

The drawing shows a device that implements a method for dynamic calibration of transducers of salinity of solutions.

Optical windows (not shown) are made in the working fluid vessel to transmit laser radiation 2 into the liquid. The device also contains a splitter 3 dp of splitting the laser beam into n rays (in the drawing) and a guide 4, according to which the graduated salinity meter 5 has the ability move along vessel 1.

At the top of vessel 1, there is a dose of a torus salt crystal (not shown) above the surface of the working fluid. The size of the salt crystals is chosen

in the range of their volume (0.001 ViO, 1) MM The lower limit of the size of salt crystals is limited by the possibility of their sedimentation in a liquid under the action of its own weight. The upper limit of the volume of crystals is limited to the formation behind the crystal during its sedimentation in a liquid of the Karmononian Track. Experimental studies allow us to consider this range as optimal for achieving the goal. The wavelength of the laser radiation is chosen from the conditions for ensuring that the spectral absorption coefficient of the laser radiation by the liquid is in the range from 2 to 1000 m,

With a lower absorption coefficient, all radiation will pass through the working fluid without noticeable absorption. With a more significant hour of radiation is delayed in the boundary layers of the liquid.

Splitter 3 in the implementation of the method can be refused if the walls of the vessel 1 are mirrored for a laser beam inclined at an angle to the vertical.

A device for implementing the method works as follows.

ten

15

Using a dispenser, a salt crystal is dipped into the liquid vessel 1, which sediments in the liquid under the influence of a gravity sipe. At the same time, dissolving in a liquid, the crystal leaves a salt trail of the same diameter, despite the reduction of its size.

The trace length is determined by the size of the crystal, the diameter is determined by the physical nature of the solvent (but not the diameter of the crystal). Therefore, if it is necessary to increase the diameter of the salt trace, then it is immersed 20

25

. ,

;

thirty

There are a number of salt crystals. The salt trail has a lifetime of about 2 minutes due to the small value of the salt diffusion coefficient in most liquids (for example, the salt diffusion coefficient in water D -10-).

Then, laser 2 is turned on and a salt trail is shot through with a series of parallel laser beams formed by a splitter 3. In this case, in the working fluid, there are 7 higher temperature zones crossing the salt trail 6.

The diffusion coefficient of heat in a liquid exceeds the coefficient of diff (} of salt reduction by two orders of magnitude (for example, the thermal diffusivity of water is equal to

ten ). Therefore, at the intersection points in a few seconds due to

35 thermal diffusion of heterogeneity in salinity (and temperature) will be absent and the salt trace 6 will take the form of a perfect cylinder.

Thus, a spatial zone is formed in the working fluid with alternation of the salinity values of the fluid and with a lifetime of about 2 minutes. Moving converter 5 along salt inhomogeneity in series with different speeds and registering its output signal, perform dynamic calibration of converter 5 The frequency of the input signal will depend on the speed of movement of converter 5. Similar dynamic calibration results can be obtained on a device in which intermittent salt labels are obtained with mirrors and a single laser beam.

If the movement of the calibrated converter 5 along the salt trace 6 starts immediately after stopping 40

45

55

31

Neither a laser pulse nor end movement during thermal non-uniformity (less than 6–8 s) during the movement time, the converter will be affected by salinity pulses of various amplitudes, which allows determining the transducer's extreme sensitivity to pulsations and the amplitude characteristic of the latter.

Another calibration mode can be provided by starting the displacement of the transducer 6–8 s after the termination of the action of laser radiation. Then a saline-type HOCTL-lack of salinity is formed.

PRI me R. Distilled water at 18 ° C was used as the working fluid, and sodium chloride crystals with a volume of 0.001–0.01 mm were used as the salt identifying salt crystals. It was used with a neodymium laser operating in a free-running mode at a wavelength of 1.06 μm, and an electrical conductivity sensor developed by the design bureau of oceanologic engineering of the Institute of Oceanology named after PP Shirshov of the USSR Academy of Sciences was used as a graduated transducer. A shadow device was used to visualize salt and thermal irregularities. It is known that the absorption coefficient of water at a wavelength of 1.06 µm – 0.12 cm, the coefficient of thermal diffusion in water is equal to – cm / s, and the diffusion coefficient of table salt in water is equal to

10- cMVc. ;

During sedimentation in water, the salt crystals in it produce a salt trace of strictly constant diameter (1.5 + 0.1) mm with an average concentration of 1.5%, more than 1 m long, and a life time of 2 minutes.

When water absorbed pulsed focused radiation from a 1 J junction laser with an energy / pulse, thermal non-uniformity (with a diameter of 1 to 2 mm in the region of the lens caustic) with an average temperature above the background of several degrees occurred. The length of the temperature inhomogeneity is cm, the lifetime is 6-8 s.

11-4

When crossing salt and heat inhomogeneities, the life time of salt inhomogeneity was reduced from 2 minutes to a few seconds. Consequently, after a few seconds, when the described experimental conditions are fulfilled, an environment with a given salinity distribution is formed in the water, which is necessary to achieve the goal.

Claims (3)

1. The method of dynamic calibration of solutions salinity converters, which consists in moving the calibrated converter relative to the environment with a known spatial distribution of salinity and simultaneously recording the output signal of the calibrated converter, characterized in that, in order to extend the working range of the dynamic calibration to the high frequencies, the medium with a known spatial distribution of salinity is created by sedimentation of a salt crystal in a stationary liquid. from 0.001 to 0.1 mm, followed by irradiation with pulse laser radiation of sections of equal length of the obtained salt trace, located at equal distances from each other, while the wavelength of the laser radiation is chosen so that the spectral absorption coefficient of the radiation by the solution is in limits from 2 to 1000 m, and the calibrated transducer is moved along the resulting salt trace. 2. Method POP.1, differing from that with the fact that the graduated transducer moves along the salt trail obtained in the time interval from 0 to 6-8 seconds after the end of irradiation with pulsed laser radiation. 3. Method POP1, characterized in that the movement of the graduated converter along the resulting salt trail is carried out 6-8 seconds after the end of the irradiation with pulsed laser radiation. Editor A.Dolinich Compiled by V.Kalechits Tehred A. Kravchuk Proofreader A. Obruchar Order 1302/44 Circulation 777 Subscription VNIIPI USSR State Committee for inventions and discoveries 113035, Moscow, Zh-35, Raushsk nab., 4/5 Production nio-polygraphic enterprise, Uzhgorod, Projecto st., 4